When universal indicator is added to a solution, the color change can indicate the approximate pH of the solution. Acids cause universal indicator solution to change from green toward red. Bases cause ...

Rainbow Tornado Explore Le Châtelier's Principle using antacid, vinegar, and universal indicator to create a colorful vortex!

Universal indicator has many different colour changes, from red for strongly acidic solutions to dark purple for strongly alkaline solutions. In the middle, neutral pH 7 is indicated by green.

Add approximately 10 mL universal indicator and stir so that the water is visibly green. Then add 3-4 drops of 6M HCl and stir until the mixture becomes red. Add 4-6 sodium hydroxide pellets. As they ...